You can't put azaleas into flower pots.

Thank you for your report!
We're tracking this issue in MCPE-128932, so this ticket is being resolved and linked as a duplicate.

If you haven't already, you might like to make use of the search feature to see if the issue has already been mentioned.

Quick Links:
📓 Bug Tracker Guidelines – 💬 Community Support – 📧 Mojang Support
📓 Project Summary – ✍️ Feedback and Suggestions – 📖 Game Wiki